JPH11304037A - valve - Google Patents

Abstract

(57) [Problem] To provide a valve which has a simple configuration, has no check valve, and does not allow the pressure on the output side to flow back to the input side. SOLUTION: A valve 4 for regulating communication between an input port 11 and an output port 12 is provided in a housing 2 so as to regulate communication between both ports, and a spring 16 for closing the valve 4 is provided. In the valve 1 in which the valve 4 is opened by external pressure against the force and the ports 11 and 12 are communicated, the housing 2 has an input port 11 and an output port 1
2 and a pressure action chamber 13 are provided.
Is supplied with a pilot pressure from an input port 11, and the valve 4 is opened by the pressure of the pressure action chamber 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve, and more particularly to a valve that opens when a predetermined pressure acts on an input port.

[0002]

2. Description of the Related Art Conventionally, a valve is a direct acting type in which the valve is opened and closed directly by using an electromagnetic valve, an external pilot type in which the external pressure is controlled by an electromagnetic valve to open and close the valve, and the input side pressure is controlled by an electromagnetic valve An internal pilot system that opens and closes a valve by operating the valve is known. For example, a valve of such a system is a 2-3 port valve for fluid control (solenoid valve / air operated valve) catalog (published in March 1996 by SMC Corporation). ).

In the direct-acting type valve, a valve is controlled by an electromagnetic valve so that an input side and an output side are connected or disconnected. Generally, when the coil of the solenoid valve is not energized, the return spring pushes the armature (shaft of the solenoid valve) downward to close the valve and the input side and the output side are closed (non-communication state). ing. Therefore, when the coil of the solenoid valve is energized, the armature is attracted toward the center of the coil, that is, toward the coil, and the input side and the output side are in communication.

The internal pilot type valve shown in FIG. 3 has a structure in which an orifice is provided inside the valve and the valve is closed by an armature against the urging force of a diaphragm spring which urges the valve in the valve opening direction. I have. In this configuration, when the coil of the solenoid valve is not energized (see FIG.
(Refer to (a)), the fluid on the input side (IN side) passes through the orifice and fills the pressure action chamber, so that the pressure on the input side is equalized through the diaphragm, and the pressure in the pressure action chamber and the armature are lowered. The valve is closed by the biasing force of the return spring that biases the valve. Then, when the coil of the solenoid valve is energized (see FIG. 4B), the armature is attracted to the coil side and the pilot orifice starts to open. Thus, the fluid filled in the pressure action chamber flows to the output side (OUT side) through the pilot orifice. As a result, the force of pushing down the valve is weakened due to the decrease in the pressure of the pressure action chamber, and the valve is opened by the assisting force of the diaphragm spring pushing up the valve (FIG. 4).
(C)).

Further, a general catalog of control equipment Ver. 1
The check valve as shown on page 775 of Koganei Co., Ltd. (issued in April 1996) has a valve body which is urged by a spring in a valve body and the valve is in a closed state. When a constant pressure acts, the valve opens and communicates with the output port.

[0006]

However, in the above-described valve, a coil or a solenoid valve is required to open and close the valve, which complicates the structure and increases the cost. Also, when the output side has a higher pressure than the input side, the output side fluid flows back to the input side, so a check valve must be provided.

Although the check valve closes the valve by the biasing force of the spring, the biasing force of the spring must be increased in order to prevent leakage between the input and output ports. As described above, when the urging force of the spring is increased, a high pressure is required to open the valve,
It will not work at low pressure.

Accordingly, the present invention has been made in view of the above problems, and has a structure in which the structure is simplified, and the fluid on the output side does not flow back to the input side, and the valve opens even at a low pressure. Is a technical task.

[0009]

A technical measure taken to solve the above-mentioned problem is to dispose a valve for restricting communication between an input port and an output port in a housing between the two ports, and dispose the valve. In a valve in which a valve is opened by external pressure against a biasing force of a spring to be in a closed state to communicate both ports, an input port, an output port,
And a pressure action chamber are provided. The pressure action chamber is supplied with pilot pressure from an input port, and the valve is opened by the pressure of the pressure action chamber.

With the above arrangement, the pressure (pilot pressure) is supplied to the pressure action chamber from the input port, and the valve is opened by the pressure of the pressure action chamber. Therefore, an electromagnetic valve for opening and closing the valve is not required. With a simple configuration, the valve can be opened by the pilot pressure.

In this case, if a communication hole communicating the input port with the pressure action chamber is provided, the pilot hole on the input side is supplied to the pressure action chamber only by providing the communication hole in the input port and the pressure action chamber. Can be opened.

Further, a piston is provided in the pressure working chamber to slide in the pressure working chamber, and a valve is connected to the piston so that the valve is opened by the operation of the piston so that the valve is closed when no external pressure acts on the piston. If the pressure on the output side becomes higher than the pressure on the input side, the pressure does not flow back from the output side to the input side, so that a check valve is not required, and the pressure applied to the pressure receiving surface of the piston Can open the valve, and it is possible to open the valve with low pressure.

Further, if a discharge hole for releasing pressure is provided in the sliding range of the piston of the housing, the pressure in the sliding range of the piston is discharged by the discharging hole when the piston slides. Will have no effect.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a valve 1 according to the present invention. The housing 2 constituting the valve 1 has an inlet 21
An input port 11 for taking in a fluid through the outlet port and an output port 12 for discharging the fluid through an outlet port 22 are provided.
A communication hole 2b that connects the ports 11 and 12 is provided. The output port side of the communication hole 2b has a tapered surface 2bb serving as an annular valve seat, and a valve element (valve) 4 is disposed so as to be able to be seated on the tapered surface 2bb. The valve body 4 has a circular shape having a surface corresponding to the inclination angle of the tapered surface 2bb provided in the housing 2, and has a screw hole at the center.
Of the shaft 3a is screwed.

A cylindrical hole 2d serving as a pressure action chamber 13 is formed in the axial direction above the input port of the housing 2, and an inner wall of the cylindrical hole 2d serves as a guide surface 2a. A seal member 31 such as an O-ring is fitted around the guide surface 2a in an outer peripheral groove, and the piston 3 having a larger diameter than the disc-shaped valve body 4 slides while maintaining the seal. The piston 3 is axially movable integrally with the valve body 4 by a shaft 3a engaged with the valve 4 by a screw. In this case, the shaft 3a is supported by a hole passing through the center of the input port 11 and the cylindrical hole 2d, and the space below the piston defined by the housing 2 and the piston 3 and the input port 1
1 is slid while the seal is maintained by a seal member 34 such as an O-ring. A disc-shaped retainer 15 receiving a spring 16 locked on the bottom surface of the input port 11 is fixed on the shaft of the piston 3 by welding or the like at an intermediate position of the shaft 3a. When no pressure is applied to the piston 3 by the urging force of 16, the valve body 4 is seated on the tapered surface (valve seat) 2bb of the housing.

On the other hand, a communication hole 14 for communicating the input port 11 with the cylindrical hole 2d is formed in the housing 2 with respect to the cylindrical hole 2d, and the communication hole 14 and the cylindrical hole 2d are formed.
The housing 2 is covered with an opening at one end of the housing 2 so as to cover the opening. In this case, the housing cover 5 covers one opening of the housing 2 in a state where an annular contact surface with the housing 2 is sealed by a sealing member 32 such as an O-ring. A space is formed by covering the housing 2 with the housing cover 5 in this manner,
This space becomes the pressure action chamber 13, and the pressure (pilot pressure) from the input port 11 is guided to the pressure action chamber 13. The pilot pressure applied to the pressure action chamber 13 moves the piston 3 to the guide surface 2 a. It can be pressed along.

On the output port side of the housing 2,
After the valve body 4 is attached to the shaft 3a of the piston 3, a sealing member 3 such as an O-ring is closed so as to close the lower opening.
3, the lower side of the housing 2 is sealed.
In this case, the housing cover 6 is fixed at the bottom of the housing 2 by a fixing member (not shown), and the inlet 21 and the outlet 22 communicate with each other when the valve body 4 is opened.

Next, the operation will be described. Inlet 21
When no external pressure acts on the pressure action chamber 13 through the communication hole 14. For this reason,
The piston 3 does not move downward because no pressure acts in the axial direction. In this case, the valve element 4 receives an upward biasing force from the retainer 15 fixed on the shaft, and the valve element 4 is seated on the tapered surface 2bb of the housing 2 to keep the valve closed.

In this state, when pressure acts on the suction port 21, the pressure at the input port 11 increases, and the pressure is led to the pressure action chamber 13 through the communication hole 14. The pressure supplied to the pressure action chamber 13 acts to press the piston 3 downward along the guide surface 2 a of the housing 2.
That is, the piston 3 transitions from the solid line state shown in FIG. As the piston 3 moves, the valve body 4 is pushed down against the urging force of the spring 16 to move away from the valve seat formed by the tapered surface 2bb, and the valve 4 is opened. As described above, when the valve element 4 is opened, the high-pressure fluid supplied to the input port 11 is guided to the output port 12, and thereafter, is discharged from the discharge port 22 and resists the urging force of the spring 16. If the pilot pressure acts on the input side, the input port 11 and the output port 12 will be in communication. Therefore, only by tuning the biasing force of the spring 16, the pressure on the input side can be suppressed to a certain pressure or less.

In this case, the pressure action chamber 13 is provided with a piston 3 which slides in the pressure action chamber, and the valve is opened by the piston operation so that the valve is closed when no external pressure acts on the piston 3. Accordingly, even if the pressure on the output side becomes higher than the pressure on the input side, the pressure does not flow back from the output side to the input side, and a check valve as in the related art is not required.

Further, even when the urging force of the spring 16 acts to securely seat the valve body 4, it is larger than the pressure receiving area of the valve body 4 which receives the pressure acting on the valve body 4 from the input port 11. Since the pressure receiving area of the piston 3 is made larger, the valve can be opened by the pressure applied to the pressure receiving surface of the piston 3. Therefore, the valve can be opened even if the pressure loss is small and the pressure applied to the suction port 21 is low.

Further, when the piston 3 receives pressure and slides along the guide surface 2a, a discharge hole 17 for releasing the pressure to the atmosphere or the like is provided in the side wall of the housing 2 in the sliding range of the piston 3. Then, the pressure in the piston slide is discharged from the discharge hole 17 when the piston slides, so that the piston easily moves.

[0024]

According to the present invention, a valve for restricting communication between an input port and an output port is provided between both ports in a housing, and an external pressure is applied against a biasing force of a spring for closing the valve. In the valve that opens the valve to communicate both ports, the housing has an input port, an output port,
And a pressure action chamber are provided, a pilot pressure from the input port is supplied to the pressure action chamber, and the valve is opened by the pressure of the pressure action chamber. (Pilot pressure) is supplied,
Since the valve is opened by the pressure of the pressure action chamber,
A solenoid valve for opening and closing the valve is not required, and the valve can be opened by the pilot pressure with a simple configuration.

In this case, if a communication hole communicating the input port with the pressure action chamber is provided, the pilot pressure on the input side is supplied to the pressure action chamber simply by providing the communication hole between the input port and the pressure action chamber. , The valve may be opened.

Further, a piston sliding in the pressure working chamber is provided in the pressure working chamber, and a valve is connected to the piston so that the valve is opened by the operation of the piston so that the valve is closed when no external pressure acts on the piston. If the pressure on the output side becomes higher than the pressure on the input side, the pressure does not flow back from the output side to the input side, so that a check valve is not required, and the pressure applied to the pressure receiving surface of the piston Can open the valve, and it is possible to open the valve with low pressure.

Further, if a discharge hole for releasing pressure is provided in the sliding range of the piston of the housing, the pressure in the sliding sill of the piston is discharged by the discharge hole when the piston slides. Does not affect

[Brief description of the drawings]

FIG. 1 is a sectional view of a valve according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA shown in FIG.

FIG. 3 is a sectional view of a conventional internal pilot valve.

FIG. 4 is a view showing an opening operation of the valve shown in FIG. 3;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve 2 Housing 3 Piston 4 Valve body (valve) 11 Input port 12 Output port 13 Pressure working chamber 14 Communication hole 16 Spring 17 Discharge hole

Claims (4)

[Claims] 1. A valve for restricting communication between an input port and an output port in a housing is provided between the two ports, and the valve is actuated by external pressure against a biasing force of a spring for closing the valve. A valve that opens the valve to communicate the two ports, wherein the housing is provided with an input port, an output port, and a pressure action chamber, and the pressure action chamber is supplied with pilot pressure from the input port; The valve is opened by the pressure of the pressure action chamber. 2. The valve according to claim 1, further comprising a communication hole communicating the input port with the pressure action chamber. 3. The pressure working chamber is provided with a piston that slides in the pressure working chamber, the valve is connected to the piston, and the piston is opened by the operation of the piston. The valve according to claim 2, wherein the valve is closed. 4. The valve according to claim 3, wherein a discharge hole for releasing pressure is provided in a sliding range of the piston of the housing.